Aqueous vehicle having emulsifying properties



Patented June 20, 1939 UNITED STATES PATENT OFFICE AQUEOUS VEHICLE HAVING EMULSIFYING PROPERTIES John a. Allison, Whittier, Calif.

No Drawing. Application July 10, 1936, Serial No. 89,980 Y 6 Claims. I

' 5 kind of vegetation.

This application is a continuation in part of my earlier co-pending application, Serial No. 759,069 filed December 24, 1934.

The specific object of this invention is to prol0 vide a vehicle of the class described which is compatible with most of the protective'agents commonly used, which may be applied to both fruit and foliage of fruit trees in a film or layer of'even and controllable thickness, which may ill be prepared and used economically, and which may readily be removed from the ripe fruit by washing with water or dilute aqueous alkalis. As is well known, most of the protective agents are applied to fruit trees in solution, dispersion l or suspension in a vehicle consisting mainly of water. For example, an agent such as nicotine would normally be entirely in solution; emulsifled petroleum oils are dispersed in the' vehicle,

while solid agents such as lead arsenate arelargely or entirely in suspension.

The vehicle, containing the agent or agents in one or more of the above conditions, is reduced 7 substances comprised in the vehicle, this coating being, so far as .possibl,. retained on the protected surfaces until or unlessit is intentionally removed.

A satisfactory aqueous vehicle for the described purpose must have all of the following characteristics:

(1) Cmnpatibility.-(a) It must be readily miscible with the agent which it is intended to convey and must not react with that agent to depreciate the valuable properties of either the agent orthe vehicle. (b) It must be capable of any desired degree of dilution with such alkaline, hard-or salty waters as may be locally available without depreciation of any of the valuable properties of the vehicle. (2) Spreading Property.- It' must have its surface tension so controlled that the minute drops of which the spray or mistis composed may, on

contact with the surface to be protected; immediately spread over that surface to form 'a continuous film of uniform thickness throughout.

(3) Supporting Property.-The liquid film initially formed on the protected surface should have or should rapidly acquire the highest viscosity consistent with the proper development of the spreading-property. This is requisite in order to avoid dripping" or "skidding (the bodily movement of the film to the lower portion of the leaf or fruit by which serious wastage maybe incurred). It 'also'restrains the tendency toward pulling or beading (the tendency of the film to gather into drops or thickened areas during the time required for the drying and ultimate fixation of the film, such concentration usually producing the burning orspotting of the protected surface) (4) Adhesive Property.The permanent film ultimately produced by drying of the'initial liquid film on the surface to be protected should be tough, coherent and strongly adherent to the surface; so that it may not become detached by the action of the wind or other atmospheric eflects. I

(5) Emulsifying Property.-Liqui ds such as petroleum products, which are insoluble in water, are applied in the dispersed form after emulsification with the vehicle, Petroleum oils as such,

or with the addition of certain substances which ever, the oleaginous agent has previously been.

treated in such manner as to make it watermiscible (e. g. the so-called soluble oils) or if the agent is of other than oleaginous character,

the emulsifying property is of no importance.

(6) Removability.--The ultimate film must be of such nature as to readily be removed from the ripe fruit by washing, this removal being requisite to bringing the fruit to salable appearance and to freeing it from all traces of poisonous or other objectionable matter.

It should be noted that one of these characteristics is to some'degree antagonistic to others. It appears to be impossible to develop the spreading characteristic 2 to the greatest possible extent without limiting the development of the supporting, adhesive, and emulsifying Properties 3-4-5), while on .the other hand thedevelop-.

ment of any oneof the last named characteristics usually accentuates the other characteristics in the same group, a

For this reason it is requisite, for the application of all the various types of protective agents, toprovidetwo aqueous vehicles: first, one in which the spreading property is developed to thefullest extent and is under complete control, this bein suited to the application of water soluble agents and of such powdered solids as have little tendency to separate or agglomerate; second, one in which the emulsifying property and, with it, the supporting and adhesive characteristics, are sufficiently developed to make it suited to the application of oils or of powders which tend to segregation from the vehicle.

The present invention is of a vehicle of the second type, in which the emulsifying property is brought to a height not heretofore attained in any compound having the spreading and other properties required in an aqueous vehicle for plant spraying. Anapplication covering a vehicle of. the first type is filed contemporaneously herewith, under the title Aqueous vehicle for plant spraying materials and bearing Serial No. 89,979.

The vehicle of the instant invention is composed of well known materials, to-wit: potassium resinate, albumin, and ammonium oleate, with sufficient water to bring these materials into solution. All of these materials have heretofore been used in aqueous spray vehicles but, so far as I am aware, they have not been used in combination. The novelty as well as the value of the invention lies in the combination itself and in the control of the properties of the compound which is afforded by varying the relative proportions of these constituents.

In the copending application I have described a vehicle having highly developed spreading properties and other properties desirable in a vehicle for plant protective materials, such as compatibility, removability, freedom from tendency to drip, skid, or head, and a high degree of adhesiveness, but substantially devoid of emulsifying value. This vehicle consists of albumin and potassium or other alkali resinate in various proportions, and the copending application discloses that neither of these materials may be used alone nor as a minor constituent of the compound but that the useful range is comprised between 80% albumin 20% resinate and albumin 10% resinate. The copending application also disclosesthat aboveabout 80% albumin the spread isdeficient andthetendencyto drip is pronounced, and that below about 70% albumin the spread decreases very rapidly and a pronounced tendency to head develops. It is also disclosed in the copending case that the spreading property is most highly developed in compounds in which the albumin constituent ranges from 65% to ."of the whole.

I have discovered that by combining with this vehicle a suitable proportion of an alkaline oleate such as ammonium oleate a strong emulsifying characteristic may be developed, the adhesion being improved, the spreading property diminished and the other desired properties being substantially unchanged.

A typical combination of this character which I have used with great success is made in the following proportions.

Ammonium oleate Percent by weight 32.0

'Albumin do 41.5 Potassium resinate do 26.5 Water; sumcient for solution This material may conveniently be prepared in the following manner. A-diSs0lve 175 pounds a1- bumin, preferably blood albumin, in say 110 gallons water: B-dissolve 108 pounds potassium resinate in about gallons water: C-mix the two solutions and add water, if necessary, to bring the volume up to 190 gallons: D-dissolve 1 gallon oleic acid in 1 gallon 26 aqua ammonia diluted with gallon water: E--mix solution C with solution D inthe proportion 4.6 parts by volume of C to 1.0 part by volume of D. The quantity of ammonia is in excess of that required to form the oleic salt and the final mixture will contain some excess ammonia. If the mixed material is to be kept for some time it may be desirable to add a further quantity of ammonia as a preservative, particularly in warm climates.

The vehicle thus prepared is compatible with almost all of the protective agents used in the form of sprays, and with hard, calcareous or salty waters. Its spreading properties are moderate only, but are suflicient for ordinary purposes. Its supporting and adhesive properties are high and it isthus particularly suited to the application of powdered materials which must be cemented to the protected surface in order to retain their effectiveness. The permanent film left on the drying of the initial liquid film is highly adherent to both leaf and fruit and is of a high degree of permanence, notwithstanding which it is completely water soluble and may readily be washed from the ripe fruit.

The outstanding propertiy of this vehicle is the truly remarkable degree to which the emulsifying characteristic is developed. The mineral oils applied to the protected surface without material separation and in the form of minute droplets in aqueous suspension. If such oils have been dosed with materials tending to lower their surface tension (for example, the partly esterified polyhydric alcohols disclosed by Knight in Patent 1,949,798) the dispersion of the oil in this vehicle is instantaneous and requires only the gentlest agitation, and the dispersion thus formed is substantially permanet even when strongly diluted, showing no free oil and only a line of free water after undisturbed standing for an hour.

In this extreme state of dispersion the oil droplets are of microscopic dimensions and the aqueous suspension may be applied to the surface to be protected with the same freedom as a true solution and without the slightest risk of damage to fruit or leaf by the concentration of the oil in spots.

In considering variations from the type formula given above it may be assumed that the spreading property will be governed largely by the relation between albumin and resinate in the compound, making allowance for the depreciation of this property by dilution with the oleate, which has substantially no spreading characteristics. Because of this depreciation it is desirable to work within such limits as to the albumin: resinate relation as give the highest spreading value, or from about 65% albumin 35% resinate to 50% albumin 50% resinate.

The emulsifying value of the compound will be controlled almost entirely by the proportion of the oleate. For spreading petroleum oils as such it may be desirable to use as much as 40% by weight of the oleate, while for use with oils dosed with surface tension lowering agents as little as 20% may suifice. The four limit formulae thus obtained will be as follows:

High emulsifying value commercial practice under ordinary conditions but are not limiting, it being possible to go to' considerably wider limits in producing vehicles for unusual conditions of use. All of these formulae disregard the water content, which may be varied at convenience so' long as sufficient be used to bring the constituents into complete solution.

Within narrow limits the materials of the above formulae may be substituted by equivalents.

For the alkaline ingredient in potassium resinate I may substitute ammonium as the full equivalent. In fact, were it not for the difiiculty in preparing the ammonium salt its substitution would be desirable because of its greater freedom from the deleterious effects of hard waters. Sodium resinate is a possible substitute for the potassium salt but is of a low order of water solu- 4 bility and requires excessive dilution.

The acid ingredient in potassium resinate is, commercially, common rosin or colophony. Obviously other resins and exudates of an acid nature might be substituted, though such substitution would in most cases be barred on the score of excessive cost.

For the alkaline ingredient in ammonium oleate I may substitute potassium, but sodium cannot be substituted because of the hardness and the reduced solubility of the resultant soap.

A further quantity of the oleate cannot be substituted for potassium resinate in the above tormulae. Both potassium resinate and albumin have spreading properties when used singly, but the spread produced by the combination of these constituents is far in excess of that of either constituent alone. The substitution of oleic or other fatty acid salt for the resinic salt does not provide this spreading property, which appears to be due to a more or less definite com- First, the substitution of casein for albumin in other than av minor proportion makes it impossible to utilize, for dilution in the field, local waters carrying material proportions oi alkali earths or metallic. salts. It will be understood that the proportion of water indicated in the description of the preparation of the first formula is not that occurring in the vehicle as actually used, but is such as to produce a concentrate adapted to packaging and shipping. For actual use in spraying this concentrate is further diluted with. more or less 2500 volumes of water which must, of course, be such as. is locally available.

Over extensive fruit growing areas the only waters obtainable for field dilution are heavily charged with lime, magnesia, chlorids, and sulfates, and when these waters are used to dilute mixtures containing caseinates,- material proportions of the casein are precipitated and rendered inactive. Further, this precipitation reduces the spreading value which it is the prime purpose of the casein to produce, and very hard waters may totally destroy the spreading characteristic. Still further, the precipitates so produced are Waterinsoluble and of a sticky and adhesive nature, and when deposited on the fruit and dried and oxidized during the ripening period, are difiicult or impossible to remove by water washing, thus leaving the washed fruit discolored,'atthe best, and poisonous in cases where toxic agents have been used. Albumin is not thus precipitated by ence of a small proportion of casein in a mixture in which the protein constituent is mainly albumin is not fatal to the value of the vehicle, but merely depreciates that value to the extent to which the substitution is carried.

The properties'of the albumin-resinate-oleate compound above described may in some cases be materially improved, particularly as to stability in storage and as to compatibility with hard waters, by the addition of a small amount of a mild alkali, sufficient to bring it to a distinctly alkaline reaction. For this purpose I prefer to use sodium silicate, sodium hexametaphosphate or sodium carbonate, or the corresponding salts of potassium.

I claim:

1-. A vehicle for plant spraying materials-comprising albumin, an alkali resinate, and an alkali oleate.

2. A vehicle for plant spraying materials comprising albumin, potassium resinate, and ammonium oleate.

3. A vehicle for plant spraying materials comprising albumin to 52%, an alkali resinate 21% to and an alkali oleate 20% 'to 40%,

all said percentages referring to totalv weight of said constituents in the dry form.

4. A vehicle for plant spraying materials comprising albumin 30% to 52%, potassium resinate 21% to 40%, and ammonium oleate 20% to 40%, all said percentages referring to total weight of said constituents in the dry form.

5. A vehicle for plant spraying materials: albumin, an alkali resinate, an alkali oleate and an excess of a mild alkali.

6. A vehicle for plant spraying materials: an aqueous solution of albumin, potassium resinate, ammonium oleate and an excess of a mild alkali.

- JOHN R. ALLISON. 

